NDK_URL := https://dl.google.com/android/repository/android-ndk-r16b-linux-x86_64.zip

NDK_ZIP := $(call download,$(NDK_URL))

NDK_EXTRACT := $(call extract,$(NDK_ZIP),android-ndk-r16b)

NDK_STANDALONE := $(WORKING)/ndk-standalone

#################################################################

# Common flags, etc. that can be used in the build

BUILD := x86_64-linux-gnu

HOST := arm-linux-androideabi

CROSS_PREFIX := $(HOST)-

TOOLCHAIN_BIN := $(NDK_STANDALONE)/bin

CROSS_CC := $(CROSS_PREFIX)clang

CROSS_CXX := $(CROSS_PREFIX)clang++

CROSS_LD := $(CROSS_PREFIX)ld

CROSS_AR := $(CROSS_PREFIX)ar

CROSS_AS := $(CROSS_PREFIX)as

CROSS_RANLIB := $(CROSS_PREFIX)ranlib

CROSS_STRIP := $(CROSS_PREFIX)strip

CROSS_PKG_CONFIG_LIBDIR := $(INSTALL)/lib/pkgconfig

CROSS_SYSROOT := $(NDK_STANDALONE)/sysroot

HOST_SYSROOT := $(CROSS_SYSROOT)

CROSS_CPPFLAGS :=

CROSS_CFLAGS :=

CROSS_CXXFLAGS := $(CROSS_CFLAGS)

COMPILE_HOST_PATH := $(TOOLCHAIN_BIN):$(PATH)

CROSS_LDFLAGS := \

-Wl,-s \

-L$(INSTALL)/lib

$(TOOLCHAIN_BIN)/$(CROSS_CC): $(NDK_EXTRACT) $(make-dirs)

$(NDK_EXTRACT)/build/tools/make_standalone_toolchain.py \

--arch arm \

--api 21 \

--stl libc++ \

--force \

--install-dir $(NDK_STANDALONE)

#################################################################

# We need a library of clang builtins

# See https://bugs.llvm.org/show_bug.cgi?id=14469

COMPILER_RT_DIR := $(TOP)/compiler-rt

COMPILER_RT_SRC := comparedf2.c mulodi4.c

COMPILER_RT_OBJDIR := $(WORKING)/compiler-rt

COMPILER_RT_OBJ := $(addprefix $(COMPILER_RT_OBJDIR)/,$(COMPILER_RT_SRC:.c=.o))

COMPILER_RT := $(INSTALL)/lib/libcompiler_rt-extras.a

$(COMPILER_RT_OBJDIR)/%.o: $(COMPILER_RT_DIR)/%.c \

$(TOOLCHAIN_BIN)/$(CROSS_CC) | $(COMPILER_RT_OBJDIR)

$(TOOLCHAIN_BIN)/$(CROSS_CC) -I$(COMPLIER_RT_DIR) -Wall -O2 -c -o $@ $<

$(COMPILER_RT): $(COMPILER_RT_OBJ) $(TOOLCHAIN_BIN)/$(CROSS_CC)

$(TOOLCHAIN_BIN)/$(CROSS_AR) rcs $@ $(COMPILER_RT_OBJ)

$(COMPILER_RT_OBJDIR):

mkdir -p $@

$(INSTALL)/lib/libc++_shared.so: $(TOOLCHAIN_BIN)/$(CROSS_CC) $(make-dirs)

cp -rfd $(NDK_STANDALONE)/$(HOST)/lib/*.so $(INSTALL)/lib

##########################################################################

# Ordering. Add CROSS_CC to PATH for stages that need it.

$(host-toolchain): $(TOOLCHAIN_BIN)/$(CROSS_CC)

$(host-toolchain): $(INSTALL)/lib/libc++_shared.so

$(host-toolchain): $(COMPILER_RT)

$(compile-host): export PATH := $(TOOLCHAIN_BIN):$(PATH)

$(compile-host-1): export PATH := $(TOOLCHAIN_BIN):$(PATH)

$(compile-host-2): export PATH := $(TOOLCHAIN_BIN):$(PATH)